Multiple-switch bank and keyboard

ABSTRACT

A multiple-switch bank is provided that generates a unique group of electrical pulses at each switch whereby each group of pulses represents a specific bit of intelligence or information to be coded and transmitted. Coding is accomplished by providing at each switch a plurality of contacts which can be brought into engagement with an equal number of code bars. Some bars are coated with a nonconductive layer whereby at the remaining bars there can be established a unique pattern of conductive electrical contacts. The switches are manually operated from a keyboard of novel design in which the keys may be arranged in the conventional pattern of a typewriter. The block with the code bars can be removed and replaced by another one in order to reprogram all the coded signals. The signals are particularly compatible with receiving equipment adapted to operate on binary codes.

United States Patent Louis A. Splevak [45] Patented Dec. 14,1971

[54] MULTIPLE-SWITCH BANK AND KEYBOARD 46 Claims, 11 Drawing Figs.

[52] US. Cl 200/5 R, 200/5 A, 200/86 R, 200/172 R 51 1111. c1 1101119/26, HOlh 3/02 [50] Field of Search 179/90 K, 90.3; 200/1, 5, 83.5,86.1, 86 R, 86 A, 172 R; 235/145 R [56] References Cited UNITED STATESPATENTS 1,882,106 10/1932 Wise 179/901 2,320,774 6/1943 Flynt zoo/5 EPrimary Examiner-.1. R. Scott Attorney-Sellers and Brace 200/5 E 200/5 AX ABSTRACT: A multipleswitch bank is provided that generates a uniquegroup of electrical pulses at each switch whereby each group of pulsesrepresents a specific bit of intelligence or information to be coded andtransmitted. Coding is accomplished by providing at each switch aplurality of contacts which can be brought into engagement with an equalnumber of code bars. Some bars are coated with a nonconductive layerwhereby at the remaining bars there can be established a unique patternof conductive electrical contacts. The switches are manually operatedfrom a keyboard of novel design in which the keys may be arranged in theconventional pattern of a typewriter. The block with the code bars canbe removed and replaced by another one in order to reprogram all thecoded signals. The signals are particularly compatible with receivingequipment adapted to operate on binary codes.

4. K UUUUUUJUJQYUUU TMUU UUUUU U Pmmfinmmmn 3.627935 SHEET 1 BF 3 4?? Yn UUUUUUJL JOJUUU [5 auuu uu u u uuuuu I 60 o o V se IIIIIIIII III IBACKGROUNDOFTHE INVENTION The present invention relates generally toelectrical switches, but more especially to a multiple-switchconstruction in which closing a selected switch generates a uniquesignal comprising one or more electrical pulses by completing one ormore electrically conductive contacts.

The use of computers and other mechanisms adapted to use intelligencebased on binary codes has given to a need for equipment especiallyadapted to converting bits of intelligence into the electrical signalsthat are based upon binary codes. Of course the equipment generating thesignals is not necessarily limited to such a use, as it may generatesignals unrelated to binary coding systems or equipment. As an example,there is a need for equipment capable of generating electrical signalsthat correspond to English text, with the several punctuation marks,spacing of words and lines, and other machine functions that arenormally found in typewriters and typesetting machines. It is customaryto generate the necessary signals in terms of a binary code and eitherto use these signals immediately to actuate suitable apparatus, or tostore the signals, as on magnetic tape, for a later use.

As typical of such a device, the present disclosure includes a codingdevice operated by a keyboard resembling a standard typewriter keyboard.It will be obvious that the construction for a coding device isindependent of the ultimate use or destination of the signal generatedby the coding device. Consequently, the present device may be regardedas a bank of switches that are individually controlled manually from akeyboard panel of suitable design. In a broader aspect of the invention,these signals may go to any type of device that responds to a particularcombination of electrical pulses and the nature of the apparatusreceiving the pulses is not limitative upon the present invention.

Thus, it ,is a general object of the present invention to provide amultiple-switch bank of novel construction for converting bits ofintelligence into unique electrical signals, each signal comprising aplurality of electrical pulses.

It is also an object of the present invention to provide apparatus ofnovel construction in which a plurality of electrical switches can bearranged to be operated individually by a plurality of manually actuatedkeys arranged in a keyboard, one example of which is a keyboardresembling a standard typewriter.

It is a further object of the invention to provide a plurality ofswitches having a novel construction that permits the advantageous useof modern photo-etching techniques.

It is also an object of the present invention to provide amultipleswitch bank which .can easily reprogrammed to'a different codesimply by exchanging one module of the switch bank.

SUMMARY OF THE INVENTION The above, as well as other, objects of thepresent invention are achieved in apparatus for producing a unique groupof electrical pulses for each of a plurality of individual bits ofintelligence by providing a keyboard panel having a plurality of movablekeys, there being one key for each such bit; and means responsive todeflection of a selected key of the keyboard to establish a uniquepattern of electrically conductive contacts with a plurality ofconductors, each of which contacts produces an electrical pulse in aconductor. The keyboard comprises a sheet of resilient material with aplurality of keys, each integral with the sheet at a resilient hingepermitting individual movement of the keys. Movement of a key deflects amovable element of the switch associated with the key, such movableelement having a plurality of contacts which are movable into engagementwith an equal plurality of fixed electrical conductors. The pattern ofelectrically conductive contacts at each switch is different and isestablished by a coating of insulating material on those conductors atwhich it is desired to avoid an electrically conductive contact.

These fixed conductors typically are a plurality of parallel bars whichpass beneath the keys of the keyboard.

BRIEF DESCRIPT ION OF THE DRAWINGS How the above, as well as other,objects and advantages of the present invention are achieved will bemore readily understood by reference to the following description and tothe annexed drawings, in which;

FIG. 1 is a plan view of a preferred form of apparatus embodying thepresent invention illustrating diagrammatically its connection tovarious examples of receiving or readout equipment.

FIG. 2 is an enlarged fragmentary vertical section taken on line 2-2 ofFIG. 1.

FIG. 3 is an enlarged fragmentary plan, with portions of the keyboardpanel and movable contact broken away, of the area indicated by the line33 in FIG. 2.

FIG. 4 is a transverse section through the apparatus on line 4-4 of FIG.2.

FIG. 5 is a plan view of the code block and the fixed contacts, removedfrom the apparatus to illustrate a preferred configuration of the codebars.

FIG. 6 is a further enlarged fragment in vertical section correspondingto the encircled area 6-6 in FIG. 4.

FIG. 7 is a fragmentary plan view of the code bars taken on line 77 ofFIG. 6.

FIG. 8 is a fragmentary vertical section through the code block on line8-8 of FIG. 6.

FIG. 9 is a fragmentary plan view, corresponding generally to FIG. 5, ofa variational form of the invention.

FIG. 10 is a transverse vertical section through the modified form ofthe invention.

FIG. 1 l is an enlarged fragmentary section corresponding to the portionof FIG. 10 encircled at l lll.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing, andparticularly to FIG. l, there is shown in plan the complete codingswitch bank indicated generally at 10. The apparatus is provided with apower supply terminal block 11 which may be connected by means of plug12 and the attached cable to any suitable source of electric power,either directcurrent or alternating current, as may be desired. Theapparatus is provided with output terminal block 14 which may connectedby plug 15 and conductor 16 to any one or more of a plurality ofinstruments capable of receiving and processing the coded electricalsignals produced by apparatus 10.

Typical of such receiving devices, but in now way limitative thereto, istypewriter l7, telephone 18 with an acoustic pickup or coupler 18a,video receiver 19, and tape punch 20. Generally speaking, the encodingswitch bank of the present invention may be incorporated into a systemoperated directly by the output signals from the encoding device or itmay be connected to any suitable readout or storage unit, near orremote, capable of utilizing the output signals. The nature or purposeof such receiver unit is not limitative upon the present invention.

The encoding apparatus provides one or more electrical switches, each ofwhich is capable of producing a unique combination of a plurality ofconnects pulses. As may be seen from FIGS. 2 and 3, the apparatuscomprises three major elements, keyboard panel 22 having a plurality ofkeys or manually operated switch actuators; movable contact assembly 24providing a plurality of movable switch contacts, there being at leastone movable contact for each key on panel 22; and code block or programplate 26 which has a plurality of encoding bars with which the movablecontacts of assembly 24 are moved into engagement by individual keys ofpanel 22, all as will be further explained. Panel 22, assembly 24 andcode block 26 are mounted in a frame 27 which holds these components inassembled position. The frame is preferably of an electricallynonconductive material to insulate the various electrical conductors,for obvious reasons.

Panel 22 is a generally flat, thin sheet of resilient material,preferably metal and typically stainless steel or other ferrous alloy.Selected areas of the panel have been treated in a manner to make theminto individual keys, each key representing some predesignated bit ofintelligence or information. In the illustrative example of theinvention disclosed herein, the panel has been patterned after thestandard typewriter keyboard, with the addition thereto of certainoperational keys which designate functions rather than alphabeticalcharacters. Thus keys 28 represent the usual alphabetical letters, bothuppercase and lowercase, numerals, punctuation marks, and the like,normally found on the standard typewriter keyboard. In a locationconventional with the standard typewriter, there is an elongated key 29which represents the usual spacebar. Keys 30 perform the function ofeffecting a shift between upper and lowercase letters of the alphabet.Other functions normally accompanying typewriting text material may beallocated to keys 31 while additional keys 32 may be assigned specialfunctions which are required only under certain circumstances or withthe particular equipment to which the switch bank is connected.

As suggested by the variety of sizes and shapes shown in FIG. 1, theindividual key portions of the panel 22 may be of any desired size andshape. In general, it is preferred that they be generally rectangular,having the same basic arrangement and location as keys on the standardtypewriter keyboard for ease of operation by one familiar with thetypewriter. Of course, this arrangement is for convenience in coding alanguage or bits of intelligence equivalent to test, and is not[imitative upon the invention.

Each key of panel 22 is formed from a portion or area of lever originalsheet and is integral therewith. Each key is freed from the adjoiningportions of the panel around the perimeter of the key except for a hingeportion at one side of the key. This construction is shown particularlyin FIGS. 3 and 6. When each of the keys is generally of a quadrilateralshape, each key is discontinuous with the surrounding sheet alongposition sides at the gap 34, as indicated in FIGS. 3 and 6, between akey portion 28 and an adjoining portion of the panel 22. They keyportion remains integral with the panel along the fourth side 35 by ahinge tang integral with and resiliently interconnecting the main bodyof panel 22 and key portion 35. The length of this hinge portion 35 canbe controlled by the configuration given to the gap 34. As may be seenin FIGS. 1 and 3, gap 34 extends along a part of the fourth side of akey 28 to reduce the length of the hinge as compared with thecorresponding dimension of the key.

This construction permits each key to be deflected downwardly by manualpressure on its upper face. This deflection of the key involves aswinging motion about its hinge 35, and the force required is reducedwhen the thickness of the sheet is reduced at the hinge line, or thelength of the hinge is reduced, or both. The resilience of the hingerestores the key to the raised or neutral position when manual pressureis released.

It has been found that a photoetching process is a particularlyeffective and economical manner of making the individual keys in thepanel. While any photoetching process may be used, this type of processgenerally involves making a film negative on which the keyboard layoutis made with the necessary degree of accuracy. This layout is thentransferred by a photographic process to the upper face of the panel,which previously has been covered with a photosensitive maskingmaterial. After exposure of the photosensitive material through the filmnegative, the masking material is washed away in those areas to beetched, in this case especially lines creating gap 34. The chemicaletching process is then carried on to the extent that in the treated oretched areas metal is removed to a depth equal to substantially onehalfthe thickness of the panel sheet. This forms one-half of the gap 34. Thesheet constituting panel 22 is preferably only a few thousandths of aninch thick, typically in the range of to thousandths of an inch and isparticularly suited to forming keys of this character by a photo etchingprocess as opposed to mechanical processes. By this first step of theprocess, each key is etched on one side of the sheet.

After this first etching step is completed, the etching process isrepeated on the reverse or opposite side of the panel sheet inregistration with the lines already etched. This second etchingoperation extends the gap 34 entirely through the panel sheet, therebyfreeing each individual key from the adjoining sheet except along thehinge portion 35 between the spaced ends of etched gap 34. The finalresulting structure is a panel having a plurality of individual keyswhich are resiliently hinged to the original panel sheet but are nowcapable of being deflected individually with respect to the plane of thesheet, such deflection taking place by bending the panel at the integralhinge 35, as indicated in FIG. 6.

Assembly 24 of movable switch contacts is disposed a short distancedirectly below panel 22. This contact assembly is likewise formed from aflat metal sheet which preferably is substantially coextensive in sizeand shape with panel 22. As shown in FIG. 3, contact assembly sheet 24has a plurality of three-sided cutout areas 40, each of which defines acontact tab 41 that, like the keys in panel 22, is free of the remainderof the sheet around three sides and hinged to the sheet at the fourthside by an integral portion 42 of the sheet. The marginal portion of atab 41 opposite hinge 42 is further subdivided to a comblike arrangementhaving a plurality of individual fingers 44. Each finger 44 is separatedfrom the ad joining finger and remains integral with the tab 44 at itsbase. How the number of these fingers is arrived at will be explainedlater.

The cutout areas 40 and the slits between fingers 44 may be formed inany suitable manner, as by stamping, diecutting, or photoetching, asabove described. Since the assembly 24 provides the movable contact ofeach of a plurality of electrical switches, a metal sheet is preferablyused to form the movable contacts as well as to provide a commonconductor connected to all the contacts. The switch assembly sheet 24 isconnected to one conductor of power terminal 11 by any suitable means.

Interposed between top panel 22 and contact assembly 24 is guide plate46 which is provided with a plurality of transversely extending bores ineach of which is located a transfer pin 47 of a suitable electricallynonconductive material. There is one transfer pin for each key in panel22, and the length of each pin is equal to the spacing between theunderside of the key above it and a tab 41 below. Thus, each pintransfers from a key of the panel to the movable contact associatedtherewith, deflection of the key to actuate the associated switchelements. Guide 46 is a relatively thick, rigid sheet or plate which isinterposed between keyboard panel 22 and the switch elements in order togive structural rigidity and stability to the apparatus. Guide plate 46functions as a frame element as well as a support and guide for thetransfer pins. It will be recalled that both sheets 22 and 24 arepreferably thin flexible members and consequently when disposedhorizontally, as indicated in the drawings, they are apt to sag whenlarge enough to contain all keys of a typewriter keyboard. Guide sheets46 not only separates these two sheets, but serves to give dimensionalstability to the entire apparatus. Sheet 46 is preferably made of asuitable nonconductive material.

The bottom element of the encoding apparatus is code block or programplate 26. This block comprises a base 50 of any suitable insulatingmaterial on the top surface of which is located a plurality of code bars52 which form the fixed contacts of each of the switches of the codingapparatus. It may be constructed by laminating a copper sheet to thebase and chemically etching away unwanted parts of the sheet to leave onthe base bars 52.

These code bars 52 are separate or discrete elements. They are arrangedparallel to each other and are laterally spaced apart. While a separaterow of code bars 52 can extend for the full length of each of the rowsof keys on panel 22, it is preferable, when the keyboard comprises morethan a single row of keys, that the codes bars of all rows beinterconnected. A series connection is effected when the code bars 52are arranged as shown in FIG. 5. This zigzag pattern enables the codebars to extend in succession under all of the keys of the entire panel.The bars terminate at one edge of block 26 where they are connectedindividually to pins on terminal block 14, this tenninal block being anysuitable well-known type of pin connector, preferably mounted on base50.

It is within the scope of the invention to provide any selected numberof code bars 52. A minimum of one or two code bars may be sufficientwith one to three keys. The keyboard panel 22 illustrated herein has asufi'icient number of keys to permit formulation and transmission ofEnglish or other language text; and for this purpose an adequate numberof combinations of pulsescan be generated with eight code bars 52. Inthis illustrative case, six of the code bars are used in differentcombinations to generate enough unique groups of electrical pulses totransmit all of the letters of the alphabet, numerals, punctuationmarks, and the like, necessary for English or other language text. Twoadditional bars are made available to transmit additional bits ofintelligence that control machine operation rather than part of themessage text. It thus becomes apparent that for any given installation,the number of code bars may be increased or decreased as required togenerate the desired number of different groups of electrical pulses forthe purpose intended.

In addition to the code bars 52, it is also desirable to add stop bars53, one at each side of the group, which act to limit the downwardtravel of the movable switch contacts thereby safeguarding againsttransverse tilting or twisting of contact assembly 24 and thepossibility of noncontact of one or more fingers with the associatedcode bar.

Because of this relationship, the tabs 41 are designed to have as manyfingers 44 along one side as the total number of bars 52 and 53.Accordingly, each tab 41 is here provided with a total of IO fingers, asmany as seen in FIG. 6.

In operation, the operator manually depresses an selected key of panel22. The operator's finger and seventh is shown in phantom lines in FIG.6. Manual pressure on the upper surface of the key 28 deflects the keydownwardly, swinging it about the hinge at 35 to the position 28a ofFIG. 6. This movement of generated 157 28 is transmitted by transfer pin47 to the associated tab 41, thereby bending the tab down and bringingthe fingers 44 into contact with code bars 52. The two outside fingers44 rest upon the inoperative stop bars 53 and serve to limit thedownward travel of the movable contact assembly and more particularly tocounteract any tendency of a group of contact fingers to tilt out of aplane parallel to the stationary contacts while moving into and out ofengagement therewith since such tilt can result in the production of anerroneous pattern of signal bits. This movement of a tab 41 in responseto deflection of the key of panel 22 produces a unique patternofelectrical contacts depending upon which of fingers -44 complete anelectrical contact with code bars 52.

The pattern of electrical contacts is controlled by covering the topsurface of each code bar 52 where no electrical contact is desired witha coating of an insulating material, as indicated at 55. This coatingmay be a piece of tape or a spray coating applied to the code bar, theinsulating material being such as to prevent an electrical circuit beingestablished between the two members 44 and 52 though mechanicallyengaged. Else where, members 44 and 52 engage conductively and transferelectric current between tab 41 and code bars 52. Nonconductingcoverings 55 are applied in such a manner that a different pattern ofelectrically conductive contacts between the fixed and movable switchcontacts is established at each of the keys of keyboard 22 with theresult that each key has its own unique pattern of electrical pulsesestablished by depressing that key.

By way of further explanation, reference to FIGS. 6 and 7 indicates thatthe first, third and seventh code bars, counting from the left, arecoated with nonconductive material 55. Consequently the electricalpulses are created by contacts in the second, fourth, fifth, sixth, andeighth bars, counting from the left. Thus, a group of five electricalimpulses is generated,

producing a uniqueel'ectrical signal which is transmitted from theapparatus through'output terminal 14 and cable 15.

In order to simulate more completely the operation of the standardtypewriter keyboard, certain keys, such as keys 30, can be assigned afunction of shifting from uppercase to lowercase letters of alphabet.This case shift is effected physically in the coding apparatus bymovement of code block 26 in a direction parallel to the longitudinalextent of code bars 52, thereby altering the' pattern of electricalcontacts made by each key and its associated tab 41.

To permit movement of code block 26, the block is preferably slidablymounted within frame 2750 that the code block is capable of limitedlinear movement to occupy any one of two or more selected operatingpositions. Mechanism for effecting this movement of the code block maybe of any suitable type, but mechanism suitable for shifting the codeblock between two positions is illustrated in FIG. 2. It comprisessolenoid 58 which is attached to frame 27. The solenoid has alongitudinally movable core 59 attached to bracket 60 which in turn isfastened to code block 26. When the solenoid is energized, plunger 59 isdrawn into the solenoid coil, movement being toward the right in FIG. 2.This movement of the plunger is transmitted through bracket 60 to codeblock 26.

The result is to shift code block 26 in the direction and amountindicated by arrow 61 in FIG. 7. It will be seen that now theillustrated tab 41 can effect electrical contact with the first, third,fourth, fifth, seventh and eighth code bars 52, conductive contact withthe second and sixth bars being prevented by the nonconductive areas 55.Thus, as a consequence of the physical shift in position of the codeblock, a change has been effected in the pattern of electrical contactsand a corresponding change has been made in the electrical pulses whichare transmitted as a group through output terminal 14. After solenoid 58is deenergized the code block is restored to its original position byforce exerted by tension spring 62 which is fastened at one end tobracket 60 and is anchored at the other end to a stationary abutment onframe 27. The spring 62 continuously biases the code block towards afirst position; then, when the code block has been moved to the rightaway from that position, returns it to its original position by movementto the left in FIG. 2.

It may be desired to shift the code block to a third operating position,and any suitable means may be provided. For example, a second solenoidwith a different range of travel may be added.

Plate 50 is mounted in frame 27 for removal to permit easy replacementof the plate by another block with a different code. One advantage ofthis' is that the same switch bank can thereby be programmed to transmita different language or a difierent code for the same language orcharacters. For this reason, the entire code block, with terminal 14,preferably slides in and out of frame 27 through an open end thereof. Inshort, by interchanging code blocks, the switch bank can be reprogrammedfor any purpose.

An electric circuit has not been shown since any suitable known circuitmay be used in the switch bank. The use of very low voltages iscontemplated; and it is preferred to use a single-point make-and-breaktype of circuit, of which several are well known, so that the fingers 44and bars 52 are not energized when electrical contact is made or broken,thus contributing to a longer life and less maintenance for theapparatus.

VARIATIONAL EMBODIMENT OF THE INVENTION There is shown in FIGS. 9, I0and I1 simplified, variational embodiment of the invention. In thisform, corresponding parts have been designated by the same referencenumerals used above, but with the addition thereto of the letter a.

From FIGS. 9 and 11, it will be noted that the hinge structure of thekeys 28, etc., on panel 22 has been modified, the resistance of thehinge to bending being controlled by reducing the thickness of the plateat the hinge rather than reducing the length of the hinge itself as inthe embodiment first described. Thus, gap 34a is now U-shaped with itsends spaced further apart than in FIG. 3, In order to reduce theresistance of the key to bending, and to define more sharply the hingepoint, a shallow groove 65 is etched at the location of the hinge at thespaced ends of gap 340.

This variational form of the invention is also characterized by omissionof guide plate 46 and loose pins 47 sliding in the guide plate totransmit to the tabs the movement of the keys of panel 22. lnstead, eachtab 41a is provided with a centrally located raised portion, typicallyin the form of button 66, against which a key 28a strikes whendepressed, as shown in H6. 11. This construction applies to operatingforce centrally to a tab 410 and causes the tab to bend about its hingeto bring its fingers 44a into engagement with code bars 520. These codebars are arranged and constructed in the same fashion as alreadydescribed and establish an electrical circuit through each conductivecontact between the code bars and the fingers of the tab. It will benoted that the construction has also been simplified by the omission ofstops 53.

As mentioned above, the invention is in no way limited by the number ofkeys in the top panel. Accordingly, in a coding device in which only arelatively small number of keys is required, the area of panel 22 andthe sheets beneath it is so reduced that the presence of an intermediateguide plate 46 is not required. Under these circumstances, thesimplified form disclosed in F lGS. 9, 10 and 11 may be entirelysatisfactory.

In summary, it is to be understood that the electrical signalsconstituting the output at terminal block 14 are composed of uniquearrangements of electrical pulses. The number of possible combinationsdepends upon the number of code bars. When eight code bars are used asin the preferred embodiment described above, each signal may containanywhere from one to eight electrical pulses distributed in any desiredmanner over one or more of the available code bars and output terminalsconnected thereto.

A compatible receiver is designed to differentiate between pulses ondifferent code bars so that even a single pulse represents a differentbit of information depending upon which of the code bars generates thatparticular signal. The duration or electrical characteristics of thesignal may or may not be of any consequence to the receiver. Thus, thereceiver may or may not differentiate between alternating current anddirect current signals; but it is assumed in this disclosure that themere existence of an electrical pulse from a code bar is sufficient toform an intelligible signal at the output terminal. From the foregoingit will be appreciated that this coding apparatus is particularly suitedfor generating electrical signals in which the pulses represent a binarycode. Accordingly, apparatus adapted to receive signals in a binary codeis compatible with the coding or programming device of the presentinvention.

From the foregoing discussion it will be apparent that various changesin the details and design or arrangement of the elements of the codingapparatus may occur to persons skilled in the art without departing fromthe spirit and scope of the present invention. Accordingly, it is to beunderstood that the foregoing description is considered to beillustrative of, rather than limitative upon, the scope of the presentinvention.

Iclaim:

l. A multiple-switch bank for producing a unique group of electricsignals for each of a plurality of individual bits of intelligence,comprising operatively assembled in combination: a keyboard comprising asingle sheet of flexible material having a separate movable key for eachbit; each of said keys comprising an integral portion of said singlesheet and separated therefrom by a looplike slot the opposite ends ofwhich extend along the opposite sides of a hinge tang having one endintegral with said sheet; and means moved by and responsive todeflection of a key of the keyboard to establish a unique pattern ofelectrical contacts with a plurality of conductors, each of whichcontacts produces an electrical signal in a conductor and which signalis isolated from said movable keys.

2. A multiple-switch bank as in claim 1 characterized in that said hingetang includes a straight groove extending transversely thereof.

3. A multiple-switch bank as in claim 1 characterized in that said meansfor establishing a unique pattern of contacts comprises: a plurality ofelectrically isolated conductors; a contact assembly having a pluralityof movable contacts each as sociated with one key and supportedresiliently at a normal position spaced from a respective one of saidconductors but movable toward and away from said conductors by movementof the associated key; and signal group control means associated withthe movable contacts for each of said keys effective to establish aunique group of electrical signals in response to depression of each ofsaid keys 4. A multiple-switch bank as in claim 3 characterized in theprovision of a plurality of said signal group control means forestablishing unique groups of electrical signals, and means forselectively shifting said signal group control means whereby depressionof a selected key creates a peculiar group of electrical signalsdepending upon which of said signal control group means is in use.

5. A multiple-switch bank as in claim 3 in which an area of selectedconductors is coated with an insulating material to prevent electricallyconductive contact; said movable contacts at selected locations in orderto establish each unique pattern of electrical signals.

6. A multiple-switch bank as in claim 3 characterized in that saidcontact assemblies are integral with and part of a common homogenoussheet of flexible conductive material, each contact assembly having aplurality of similar flexible fingers each aligned with a respective oneof said conductors and deflectable in unison by an associated one ofsaid keys toward said conductors.

7. A multiple-switch bank as in claim 3 characterized in that eachcontact assembly is an articulated member comprising: a flexible striphingedly mounted at one end and terminating at the opposite end on aplurality of integral fingers, there being one finger for each of saidconductors.

8. A multiple-switch bank as in claim 1 characterized in that saidmovable keys are arranged in at least one row and said means toestablish a unique pattern of electrical contacts comprises: a pluralityof fixed conductors extending parallel to and spaced from the row ofkeys and a plurality of resiliently mounted movable contacts arrangedbetween each of said keys and said conductors, there being a movablecontact for each of said conductors associated with and movable by eachkey toward and away from engagement with said conductors,

9. A multiple-switch bank as in claim 3 characterized in the provisionof a rigid guide plate supported beneath and parallel to said flexiblekeyboard sheet, and a plurality of transfer pins slidably mounted insaid guide plate with their opposite ends bearing against associatedones of said keys and said contact assemblies and individually movablein response to movement of an associated one of said keys.

10. A multiple-switch bank as in claim 1 in which said plurality ofconductors and said means for establishing a unique pattern ofelectrical contacts includes means for changing the pattern ofelectrical contacts.

11. A multiple-switch bank that comprises operatively assembled incombination: a keyboard having a plurality of independently operableresilient keys fixed to a first sheet; a second and conductive flexiblesheet having a plurality of groups of movable contacts each group ofwhich is movable in unison by an associated one of said keys, a codeblock operatively associated with said groups of contacts and includingsaid plurality of conductors and means associated therewith forestablishing a unique pattern of electrical signals each time a key isdepressed to complete an electric circuit between certain of saidmovable contacts and certain of said conductors, and means for shiftingsaid code block to an alternate position to change the pattern ofconductive contacts between each of said groups of contacts and saidplurality of conductors.

12. A multiple-switch bank as in claim 11 characterized in that saidcode block is readily replaceable with a code block providing adifferent unique pattern of electrical signals at each key.

13. A multiple-switch bank as in claim 11 characterized in that saidcode block has a base of nonconducting material fixedly supporting saidconductors in spaced-apart parallel relation, selected areas of certainof said conductors opposite each group of movable contacts being coveredwith insulating means positioned to prevent formation of an electricallyconductive contact between that conductor and an associated one of saidmovable contacts.

14. An article of manufacture suitable for use in opening and closing anelectrical circuit not in circuit with said article of manufacture, saidarticle comprising a thin sheet of resilient material having arelatively large area key portion separated from the remainder of saidsheet except for a relatively small area hinge tang confinedto onelateral side of said key portion, said hinge tang being integral withboth said sheet and with said key portion and effective to restore saidkey portion repeatedly to the nonnal position thereof each time aftersaid key portion has been deflected from said normal position to controlan electric circuit not in circuit with said article of manufacture.

15. An article of manufacture as defined in claim 14 characterized inthat the normal position of said key portion is generally in the planeof said sheet of resilient material.

16. An article of manufacture as defined in claim 14 characterized inthat said key portion has a surface area at least coextensive in sizewith the tip of an operators fingertip.

17. An article of manufacture as defined in claim 14 characterized inthe provision of housing means supporting said sheet of resilientmaterial and including said sheet as one exposed surface of said housingmeans.

18. An article of manufacture as defined in claim 17 characterized inthe provision within said housing means of a plurality of electricalconductors normally out of conducting contact with one another andoperatively associated with said key portion for movement intoconducting contact so long as said key portion is held flexed out of thenormal position thereof in a predetermined contact closing direction.

19. An article of manufacture as defined in claim 14 characterized inthat said sheet of resilient material is provided with a plurality ofsaid key portions each similarly integral with said sheet throughsimilar hinge tangs.

20. An article of manufacture as defined in claim 19 characterized inthat said key portions are bordered by a narrow generally C-shaped slotelectroetched through said sheet and having the slot ends terminating atthe lateral edges of said hinge tang.

21. An article of manufacture as defined in claim 19 characterized inthat a plurality of said hinge tangs have substantially identicalflexing characteristics and whereby substantially identical touchpressure applied to each by a tip of an operators finger suffices tobring said plurality of electrical conductors associated with thedepressed one of said keys into conducting contact.

23. An article of manufacture as defined in claim 21 characterized inthat each one of said key portions is effective when deflected to bringthe associated conductors into conducting relationship to create a groupof signals in electrical circuitry connected therewith which pulses arein predetermined time phase relationship to one another and distinctlydifferent from the group of signals created upon the closing of other ofsaid key portions 23. An article of manufacture as defined in claim 22characterized in that said key portions are closely spaced to oneanother in rows and conveniently arranged for manipulation by thefingers of an operators hands without need for lateral movement of thehands.

24. An article of manufacture as defined in claim 21 characterized inthat said electrical conductors lie in closely spaced side-by-siderelation and extend transversely of consecutive ones of said keyportions, a plurality of conductive fingers operatively associated witheach of said key portions and aligned with a respective one of saidconductors for simultaneous movement toward and away from saidconductors in response to flexing of the associated key portion. andbarrier means interposed in the path of movement of selected ones ofsaid conductive fingers preventing contact thereof with its associatedconductor.

25. An article of manufacture as defined in claim 24 characterized inthat said barrier means comprises a nonconductive film.

26. An article of manufacture as defined in claim 25 characterized inthat said nonconductive film is adherent to selected areas of saidconductors, and adjacent areas of said conductors being exposed.

27. An article of manufacture as defined in claim 26 characterized inthe provision of means for shifting said conductive fingers and saidconductors relative to one another thereby to vary the particularconductors having exposed areas and film covered areas in the path ofmovement of said conductive fingers.

28. An article of manufacture as defined in claim 27 characterized inthat said shifting means includes manually operable means in closeproximity to said key portions and manipulatable by the operator withoutneed for moving his fingers from their normal position overlying saidkey portions.

29. An article of manufacture as defined in claim 27 characterized inthat said shifting means includes electromechanical means controlled byflexing a selected one of said key portions.

30. An encoding device for creating a multiplicity of distinctive groupsof electrical signals each group of which is representative of a unit ofdistinctive intelligence, said device comprising: a plurality ofelectrical conductors supported in side-by-side relation opposite aplurality of sets of conductive fingers, at least a majority of saidsets of fingers including a separate finger positioned for movementtoward and away from a related one of said conductors, a multiplicity ofkeys operatively associated with a respective one of said sets offingers, said keys being operable independently of one another andmounted on a common support member, and barrier means interposed betweensaid sets of fingers and said conductors and including more than one setof distinctively arranged barrier patterns contiguous to one another andselectively usable to bar contact of certain fingers with saidconductors whereby flexing of one of said keys creates one of aplurality of distinctive bits of electrical signals representingdistinctive intelligence and wherein the particular group of distinctivebit signals produced depends on which of said barrier patterns is in us.1

31. An encoding device as defined in claim 30 characterized in that saidbarrier means comprises an insulative film applied to selected areasonly of said conductors.

32. An encoding device as defined in claim 31 characterized in theprovision of means for moving said conductors and said sets of fingersrelative to one another thereby to interpose a different one of saidplurality of distinctive barrier patterns between said sets of fingersand said conductors thereby to change the coded groups of bit signalscreated upon flexing a selected one of said keys.

33. An encoding device as defined in claim 30 characterized in that saidgroups of conductive fingers are an integral part of a common sheet ofresilient conductive material.

34. An encoding device as defined in claim 30 characterized in that saidkeys are an integral part of a common sheet of resilient material.

35. An encoding device as defined in claim 34 characterized in thatplurality of said hinge tangs connecting said keys to the main body ofsaid common sheet are identical as respects their resistance to flexingfrom their normal stable positions.

36. An encoding device as defined in claim 34 characterized in that theperipheries of said keys and the opposite lateral edges of said hingetangs are separated from the main body of said common resilient sheet bynarrow slots.

37. An encoding device as defined in claim 36 characterized in that saidslots are electroetched through said sheet of resilient material.

38. In combination, a keyboard having multiple keys each operable toactuate an associated group of resilient contacts movable interconnectedfor movement in unison relative to a group of normally stationarycontacts to produce a distinctive group of electric signals eachrepresenting an individual bit of intelligence, said stationary contactsincluding a pair of stop contacts spaced to either side of the centerones of said stationary contacts and each of said pairs ofcontactscooperating with an associated one of said movable contacts tohold said group of resilient contacts properly positioned for positivecontact with a respective one of said stationary contacts as theassociated group actuating key is operated.

39. The combination defined in claim 37 characterized in that certain ofsaid stationary contacts have areas thereof in the path of each of saidgroups of resilient contacts coated with a film of nonconductivematerial and others thereof uncoated and wherein the pattern of coatedand uncoated areas differs for each of said groups of resilient movablecontacts whereby the actuation of each key produces a different patternof bits of intelligence.

40. The combination defined in claim 38 characterized in that said pairof stop contacts are additionally effective upon one thereof engagingthe juxtaposed one of said resilient contacts before the other of saidstop contacts engages its juxtaposed resilient contact to tilt all ofthe resilient contacts of that group in a direction to counteract thetilt error thereby to assure precise and substantially uniformengagement of each resilient contact with its associated stationarycontact.

41. The combination defined in claim 37 characterized in in that saidgroups of resilient movable contacts are formed as an integralhomogenous part of the same sheet of thin resilient metallic material.

42. The combination defined in claim 40 characterized in that saidmovable contacts comprise slender fingers lying parallel to one anotherwith one set of adjacent ends connected to one another, and meansoperable by theassociated one of said keys for applying pressure to theassociated group of said fingers adjacent said one set of adjacent endsof said fingers thereby to actuate said group of fingers in unison.

43. The combination defined in claim 41 characterized in that each ofsaid groups of movable contacts is formed as an integral part of acommon sheet of resilient metallic material.

44. The combination defined in claim 39 characterized in that said pairof stop contacts is located outwardly of and along the opposite lateraledges of the remainder of said stationary contacts.

45. The combination defined in claim 37 characterized in that theengagement of either of said pair of stop contacts with the associatedresilient contact of any of said groups of resilient contacts in advanceof the other is automatically effective to tilt said group of resilientcontacts in a direction to counteract the tilt error and to bring bothof said pair of stop contacts into firm engagement with their respectiveresilient contacts.

46. The combination defined in claim 37 characterized in that saidstationary contacts comprise a plurality of conductors common to andpositioned in the path of the group of movable contacts associated witheach of said keys.

1. A multiple-switch bank for producing a unique group of electricsignals for each of a plurality of individual bits of intelligence,comprising operatively assembled in combination: a keyboard comprising asingle sheet of flexible material having a separate movable key for eachbit; each of said keys comprising an integral portion of said singlesheet and separated therefrom by a looplike slot the opposite ends ofwhich extend along the opposite sides of a hinge tang having one endintegral with said sheet; and means moved by and responsive todeflection of a key of the keyboard to establish a unique pattern ofelectrical contacts with a plurality of conductors, each of whichcontacts produces an electrical signal in a conductor and which signalis isolated from said movable keys.
 2. A multiple-switch bank as inclaim 1 characterized in that said hinge tang includes a straight grooveextending transversely thereof.
 3. A multiple-switch bank as in claim 1characterized in that said means for establishing a unique pattern ofcontacts comprises: a plurality of electrically isolated conductors; acontact assembly having a plurality of movable contacts each associatedwith one key and supported resiliently at a normal position spaced froma respective one of said conductors but movable toward and away fromsaid conductors by movement of the associated key; and signal groupcontrol means associated with the movable contacts for each of said keyseffective to establish a unique group of electrical signals in responseto depression of each of said keys
 4. A multiple-switch bank as in claim3 characterized in the provision of a plurality of said signal groupcontrol means for establishing unique groups of electrical signals, andmeans for selectively shifting said signal group control means wherebydepression of a selected key creates a peculiar group of electricalsignals depending upon which of said signal control gRoup means is inuse.
 5. A multiple-switch bank as in claim 3 in which an area ofselected conductors is coated with an insulating material to preventelectrically conductive contact; said movable contacts at selectedlocations in order to establish each unique pattern of electricalsignals.
 6. A multiple-switch bank as in claim 3 characterized in thatsaid contact assemblies are integral with and part of a commonhomogenous sheet of flexible conductive material, each contact assemblyhaving a plurality of similar flexible fingers each aligned with arespective one of said conductors and deflectable in unison by anassociated one of said keys toward said conductors.
 7. A multiple-switchbank as in claim 3 characterized in that each contact assembly is anarticulated member comprising: a flexible strip hingedly mounted at oneend and terminating at the opposite end in a plurality of integralfingers, there being one finger for each of said conductors.
 8. Amultiple-switch bank as in claim 1 characterized in that said movablekeys are arranged in at least one row and said means to establish aunique pattern of electrical contacts comprises: a plurality of fixedconductors extending parallel to and spaced from the row of key; and aplurality of resiliently mounted movable contacts arranged between eachof said keys and said conductors, there being a movable contact for eachof said conductors associated with and movable by each key toward andaway from engagement with said conductors.
 9. A multiple-switch bank asin claim 3 characterized in the provision of a rigid guide platesupported beneath and parallel to said flexible keyboard sheet, and aplurality of transfer pins slidably mounted in said guide plate withtheir opposite ends bearing against associated ones of said keys andsaid contact assemblies and individually movable in response to movementof an associated one of said keys.
 10. A multiple-switch bank as inclaim 1 in which said plurality of conductors and said means forestablishing a unique pattern of electrical contacts includes means forchanging the pattern of electrical contacts.
 11. A multiple-switch bankthat comprises operatively assembled in combination: a keyboard having aplurality of independently operable resilient keys fixed to a firstsheet; a second and conductive flexible sheet having a plurality ofgroups of movable contacts each group of which is movable in unison byan associated one of said keys, a code block operatively associated withsaid groups of contacts and including said plurality of conductors andmeans associated therewith for establishing a unique pattern ofelectrical signals each time a key is depressed to complete an electriccircuit between certain of said movable contacts and certain of saidconductors, and means for shifting said code block to an alternateposition to change the pattern of conductive contacts between each ofsaid groups of contacts and said plurality of conductors.
 12. Amultiple-switch bank as in claim 11 characterized in that said codeblock is readily replaceable with a code block providing a differentunique pattern of electrical signals at each key.
 13. A multiple-switchbank as in claim 11 characterized in that said code block has a base ofnonconducting material fixedly supporting said conductors inspaced-apart parallel relation, selected areas of certain of saidconductors opposite each group of movable contacts being covered withinsulating means positioned to prevent formation of an electricallyconductive contact between that conductor and an associated one of saidmovable contacts.
 14. An article of manufacture suitable for use inopening and closing an electrical circuit not in circuit with saidarticle of manufacture, said article comprising a thin sheet ofresilient material having a relatively large area key portion separatedfrom the remainder of said sheet except for a relatively small areahinge tang confined to one lateral side of said key portion, said hingetAng being integral with both said sheet and with said key portion andeffective to restore said key portion repeatedly to the normal positionthereof each time after said key portion has been deflected from saidnormal position to control an electric circuit not in circuit with saidarticle of manufacture.
 15. An article of manufacture as defined inclaim 14 characterized in that the normal position of said key portionis generally in the plane of said sheet of resilient material.
 16. Anarticle of manufacture as defined in claim 14 characterized in that saidkey portion has a surface area at least coextensive in size with the tipof an operator''s fingertip.
 17. An article of manufacture as defined inclaim 14 characterized in the provision of housing means supporting saidsheet of resilient material and including said sheet as one exposedsurface of said housing means.
 18. An article of manufacture as definedin claim 17 characterized in the provision within said housing means ofa plurality of electrical conductors normally out of conducting contactwith one another and operatively associated with said key portion formovement into conducting contact so long as said key portion is heldflexed out of the normal position thereof in a predetermined contactclosing direction.
 19. An article of manufacture as defined in claim 14characterized in that said sheet of resilient material is provided witha plurality of said key portions each similarly integral with said sheetthrough similar hinge tangs.
 20. An article of manufacture as defined inclaim 19 characterized in that said key portions are bordered by anarrow generally C-shaped slot electroetched through said sheet andhaving the slot ends terminating at the lateral edges of said hingetang.
 21. An article of manufacture as defined in claim 19 characterizedin that a plurality of said hinge tangs have substantially identicalflexing characteristics and whereby substantially identical touchpressure applied to each by the tip of an operator''s finger suffices tobring said plurality of electrical conductors associated with thedepressed one of said keys into conducting contact.
 23. An article ofmanufacture as defined in claim 21 characterized in that each one ofsaid key portions is effective when deflected to bring the associatedconductors into conducting relationship to create a group of signals inelectrical circuitry connected therewith which pulses are inpredetermined time phase relationship to one another and distinctlydifferent from the group of signals created upon the closing of other ofsaid key portions
 23. An article of manufacture as defined in claim 22characterized in that said key portions are closely spaced to oneanother in rows and conveniently arranged for manipulation by thefingers of an operator''s hands without need for lateral movement of thehands.
 24. An article of manufacture as defined in claim 21characterized in that said electrical conductors lie in closely spacedside-by-side relation and extend transversely of consecutive ones ofsaid key portions, a plurality of conductive fingers operativelyassociated with each of said key portions and aligned with a respectiveone of said conductors for simultaneous movement toward and away fromsaid conductors in response to flexing of the associated key portion,and barrier means interposed in the path of movement of selected ones ofsaid conductive fingers preventing contact thereof with its associatedconductor.
 25. An article of manufacture as defined in claim 24characterized in that said barrier means comprises a nonconductive film.26. An article of manufacture as defined in claim 25 characterized inthat said nonconductive film is adherent to selected areas of saidconductors, and adjacent areas of said conductors being exposed.
 27. Anarticle of manufacture as defined in claim 26 characterized in theprovision of means for shifting said conductive fingers and saidconductors relative to one another thEreby to vary the particularconductors having exposed areas and film covered areas in the path ofmovement of said conductive fingers.
 28. An article of manufacture asdefined in claim 27 characterized in that said shifting means includesmanually operable means in close proximity to said key portions andmanipulatable by the operator without need for moving his fingers fromtheir normal position overlying said key portions.
 29. An article ofmanufacture as defined in claim 27 characterized in that said shiftingmeans includes electromechanical means controlled by flexing a selectedone of said key portions.
 30. An encoding device for creating amultiplicity of distinctive groups of electrical signals each group ofwhich is representative of a unit of distinctive intelligence, saiddevice comprising: a plurality of electrical conductors supported inside-by-side relation opposite a plurality of sets of conductivefingers, at least a majority of said sets of fingers including aseparate finger positioned for movement toward and away from a relatedone of said conductors, a multiplicity of keys operatively associatedwith a respective one of said sets of fingers, said keys being operableindependently of one another and mounted on a common support member, andbarrier means interposed between said sets of fingers and saidconductors and including more than one set of distinctively arrangedbarrier patterns contiguous to one another and selectively usable to barcontact of certain fingers with said conductors whereby flexing of oneof said keys creates one of a plurality of distinctive bits ofelectrical signals representing distinctive intelligence and wherein theparticular group of distinctive bit signals produced depends on which ofsaid barrier patterns is in use.
 31. An encoding device as defined inclaim 30 characterized in that said barrier means comprises aninsulative film applied to selected areas only of said conductors. 32.An encoding device as defined in claim 31 characterized in the provisionof means for moving said conductors and said sets of fingers relative toone another thereby to interpose a different one of said plurality ofdistinctive barrier patterns between said sets of fingers and saidconductors thereby to change the coded groups of bit signals createdupon flexing a selected one of said keys.
 33. An encoding device asdefined in claim 30 characterized in that said groups of conductivefingers are an integral part of a common sheet of resilient conductivematerial.
 34. An encoding device as defined in claim 30 characterized inthat said keys are an integral part of a common sheet of resilientmaterial.
 35. An encoding device as defined in claim 34 characterized inthat a plurality of said hinge tangs connecting said keys to the mainbody of said common sheet are identical as respects their resistance toflexing from their normal stable positions.
 36. An encoding device asdefined in claim 34 characterized in that the peripheries of said keysand the opposite lateral edges of said hinge tangs are separated fromthe main body of said common resilient sheet by narrow slots.
 37. Anencoding device as defined in claim 36 characterized in that said slotsare electroetched through said sheet of resilient material.
 38. Incombination, a keyboard having multiple keys each operable to actuate anassociated group of resilient contacts movable interconnected formovement in unison relative to a group of normally stationary contactsto produce a distinctive group of electric signals each representing anindividual bit of intelligence, said stationary contacts including apair of stop contacts spaced to either side of the center ones of saidstationary contacts and each of said pairs of contacts cooperating withan associated one of said movable contacts to hold said group ofresilient contacts properly positioned for positive contact with arespective one of said stationary contacts as the associated groupactuating key is operated.
 39. The combination defined in claim 37characterized in that certain of said stationary contacts have areasthereof in the path of each of said groups of resilient contacts coatedwith a film of nonconductive material and others thereof uncoated andwherein the pattern of coated and uncoated areas differs for each ofsaid groups of resilient movable contacts whereby the actuation of eachkey produces a different pattern of bits of intelligence.
 40. Thecombination defined in claim 38 characterized in that said pair of stopcontacts are additionally effective upon one thereof engaging thejuxtaposed one of said resilient contacts before the other of said stopcontacts engages its juxtaposed resilient contact to tilt all of theresilient contacts of that group in a direction to counteract the tilterror thereby to assure precise and substantially uniform engagement ofeach resilient contact with its associated stationary contact.
 41. Thecombination defined in claim 37 characterized in that said groups ofresilient movable contacts are formed as an integral homogenous part ofthe same sheet of thin resilient metallic material.
 42. The combinationdefined in claim 40 characterized in that said movable contacts compriseslender fingers lying parallel to one another with one set of adjacentends connected to one another, and means operable by the associated oneof said keys for applying pressure to the associated group of saidfingers adjacent said one set of adjacent ends of said fingers therebyto actuate said group of fingers in unison.
 43. The combination definedin claim 41 characterized in that each of said groups of movablecontacts is formed as an integral part of a common sheet of resilientmetallic material.
 44. The combination defined in claim 39 characterizedin that said pair of stop contacts is located outwardly of and along theopposite lateral edges of the remainder of said stationary contacts. 45.The combination defined in claim 37 characterized in that the engagementof either of said pair of stop contacts with the associated resilientcontact of any of said groups of resilient contacts in advance of theother is automatically effective to tilt said group of resilientcontacts in a direction to counteract the tilt error and to bring bothof said pair of stop contacts into firm engagement with their respectiveresilient contacts.
 46. The combination defined in claim 37characterized in that said stationary contacts comprise a plurality ofconductors common to and positioned in the path of the group of movablecontacts associated with each of said keys.